tbuckley/cabot-search huggingface dataset:
Abstract 1316: Immune cell dysfunction is enhanced in a mouse model of obesity-associated breast cancer lung metastasis
Authors: Abbey E. Williams, Lisa M. Arendt
Journal: Cancer Research (2023)

Abstract Obesity is known to worsen the overall prognosis of breast cancer patients. Breast cancer patients with a body mass index (BMI) of ≥30 kg/m2 have an increased risk for metastatic disease compared to patients with a BMI in the normal range. Further studies are necessary to understand the mechanisms driving increased breast cancer metastasis in obese patients, particularly to the lung. Although immune cells like neutrophils and myeloid derived suppressor cells have been studied in breast cancer metastasis of the lung, little is known how adaptive immune cells function in metastatic niche of the lung in obesity. To investigate these gaps, we fed 3-week-old female FVB/N mice either a low-fat diet (LFD) or high-fat diet (HFD) for 16 weeks to induce obesity. We then injected estrogen receptor positive (ER+) TC2 cells into the mammary fat pad. Tumors grew to 0.5 cm in diameter then were surgically removed. Lung tissue was collected 8 weeks after tumor removal to examine progression of metastatic disease, and T cell populations were quantified in metastatic lung tissue from obese and lean mice using flow cytometry. Lungs from obese mice showed a significant increase of total immune cells (CD45) and a decrease in total T cells and natural killer cells (NK) compared with controls. CD3+ cells and CD8+ T cells from obese mice expressed higher levels of programmed cell death protein-1 (PD1), a marker of T cell dysfunction. These results suggest that T cells from the lungs of obese mice may have a greater level of T cell dysfunction than controls. To further investigate how obesity alters the function of T cells, CD45+ cells were sorted from lungs from lean and obese mice with and without metastasis, and gene expression was examined using the Nanostring nCounter Immune Exhaustion panel. Immune cells from the lungs of obese non-tumor-bearing mice showed increased expression of NK exhaustion markers and increased TCR signaling. In metastatic lungs from obese mice, immune cells also showed impaired interferon and tumor necrosis factor signaling and an increase in genes associated with exhaustion in NK cells. Further analysis showed upregulated expression of genes associated with senescence in immune cells from metastatic lungs of obese mice. These data suggest that obesity may increase dysfunctional states of T cells and NK cells, leading to enhanced metastatic growth of breast cancer cells. Citation Format: Abbey E. Williams, Lisa M. Arendt. Immune cell dysfunction is enhanced in a mouse model of obesity-associated breast cancer lung metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1316.
Abstract 2618: IQGAP3 regulates intra-cellular Ras signaling and intra-tumoral malignant cycles via TGFβ signaling
Authors: Mitsuhiro Shimura, Pang SHUCHIN, Junichi Matsuo, Linda Shyue Chuang, Yoshiaki Ito
Journal: Cancer Research (2023)

Abstract Scaffold protein IQ motif-containing GTPase-activating protein 3 (IQGAP3; IQ3) is a member of the multifunctional IQGAP family. The interaction between IQ3 and Ras-ERK signaling has been reported, but how IQ3 regulates Ras-ERK signaling in malignancies is still unclear. The purpose of this study is to elucidate the role of IQ3 in coordinating diverse pathways, such as ERK-Ras and TGFβ in gastric cancer (GC).According to Stomach Adenocarcinoma of TCGA Pan-Cancer Atlas, the frequency of gene mutations is high in TP53 (60.1%), RTK-Ras (51.8%), and TGFβ pathways (36.4%). Gene Set Enrichment Analysis (GSEA) indicated that KRAS signaling was significantly downregulated after IQ3 knockdown (KD) in three GC cell lines (AGS, NUGC3, Hs746T). Ingenuity upstream regulator analysis (IPA) of RNA sequencing data revealed that TGFβ1, the top-ranked growth factor, is significantly inhibited after IQ3 KD. Immunoblot analysis showed that IQ3 KD led to suppression of TGFβ-induced phosphorylation of MEK/ERK in three GC cell lines, particularly NUGC3. While TGFβ treatment promoted invasion and migration in transwell migration assays, IQ3 KD significantly diminished TGFβ-mediated cell migration. In vivo, the size and volume of subcutaneous tumors from IQ3 KD NUGC3 cells were significantly smaller than that from Control (Ctrl) cells. According to RNA sequencing using bulk tumors, mouse stromal cells in Ctrl tumors showed significantly higher expression of acta2, fap, pdgfa, which are the markers of cancer-associated fibroblasts, than in IQ3 KD tumors. The TGFβ1 expression levels in the NUGC3 xenograft and mouse stromal cells harvested from Ctrl were significantly higher than that from IQ3 KD, respectively. Additionally, digital spatial profiler (DSP) GeoMx evaluation of the intra-tumoral expressions from the human xenograft and mouse stromal cells showed that the mouse stromal cells from Ctrl expressed significantly higher acta2 and tgfβ1 than that from IQ3 KD. Furthermore, metastasis assays via tail vein injection in vivo showed dramatically lesser lung metastases from IQ3 KD cells than that from Ctrl cells. This study shows that IQ3 KD suppressed Ras signaling and blocked upstream regulator TGFβ1 in vitro. The stromal cells in the IQ3 KD xenografts showed a reduced population of cancer-associated fibroblasts in vivo. Consequently, tumorigenesis and metastasis were strongly suppressed after IQ3 KD. IQ3 is thus a highly relevant therapy target in GC. Citation Format: Mitsuhiro Shimura, Pang SHUCHIN, Junichi Matsuo, Linda Shyue Chuang, Yoshiaki Ito. IQGAP3 regulates intra-cellular Ras signaling and intra-tumoral malignant cycles via TGFβ signaling [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2618.
Abstract 6275: DW91170: A novel potent EZH1/2 dual inhibitor for lymphoma treatment
Authors: Doc-Gyun Jeong, Woon Heo, DongHyuk Shin, Yeonkyung Oh, Sangho Lee, Seongsu Jeong, Whuijung Park, Jiyoung Woo, Chanseok Jeon, Subin Kim, Jaekyung Lim, Yun-Ha Hwang
Journal: Cancer Research (2023)

Abstract EZH2(Enhancer of zeste homolog2) is a catalytic subunit of PRC2 (polycomb repressive complex 2) for chromatin remodeling through methyl transfer activity. Previous studies have reported correlation between EZH2 and cancer progression with overexpression and mutations in various cancers. EZH1, homolog of EZH2, also has been known to role in development and progression of cancers by complementarily replacing EZH2. In recent researches, EZH1/2 dual inhibition showed global epigenetic modification on histone methylation and acetylation. Also, cancers associated with change in epigenetic factors such as mutations in subunit of SWI/SNF responded on EZH1/2 dual inhibition. Therefore, EZH1/2 dual inhibition is expected to be an effective strategy for cancer treatment. Herein, we present a novel potent EZH1/2 dual inhibitor, DW91170, as a promising candidate for treatment of lymphoma with improved anti-cancer activity. DW91170 selectively inhibited EZH1 and EZH2 enzyme activity. DW91170 brought about histone modification by reducing tri-methylation and enhancing acetylation of H3K27, which increased expression of target genes and cell cycle arrest was confirmed by treatment of DW91170. DW91170 showed effective tumor growth inhibition in two types of EZH2 hot spot mutation models. In Pfeiffer (A677 mutation) and WSU-DLCL2 (Y641 mutation) CDX models, DW91170 showed improved tumor regression activity with no significant abnormal signs such as weight loss. In order to verify the potential of DW91170 in R/R-lymphoma patients, the anti-cancer effect was evaluated in Rituximab-resistant cell line and R/R-DLBCL patient-derived PDX model. As a result, DW91170 efficiently inhibited Rituximab-resistant cell proliferation and suppressed tumor growth in R/R-DLBCL PDX model more significantly compared to other EZH inhibitors. Moreover, DW91170 has a good absorption profile that works in a physiological condition. Taken together, we demonstrated that DW91170, a dual epigenetic regulator of EZH1 and EZH2, showed great anti-tumor activities in various lymphoma cell lines and animal models such as CDX and PDX. We are currently trying to expand indication into solid tumor to find a targetable population in clinical trials. Citation Format: Doc-Gyun Jeong, Woon Heo, DongHyuk Shin, Yeonkyung Oh, Sangho Lee, Seongsu Jeong, Whuijung Park, Jiyoung Woo, Chanseok Jeon, Subin Kim, Jaekyung Lim, Yun-Ha Hwang. DW91170: A novel potent EZH1/2 dual inhibitor for lymphoma treatment. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6275.
Abstract 122: The subclonal dynamics of gross ploidy alterations in TNBC cells under chemotherapeutic pressure
Authors: Andrea L. Gardner, Lan Zheng, Patrik Parker, Kennedy Howland, Daylin Morgan, Amy Brock
Journal: Cancer Research (2023)

Abstract Solid tumors such as triple-negative breast cancer (TNBC) have characteristically high rates of aneuploidy and polyploidy. Chromosome-level aneuploidies are known to arise through errors in cytokinesis, but many of the mechanisms which drive large-scale ploidy alterations such as whole genome doubling (WGD) are still under investigation. WGD and subsequent ploidy reduction has been implicated as a key event in cancer evolution across patient samples. Further, in vitro studies have suggested that cells may undergo polyploidization to survive certain chemotherapies. Here, we apply lineage tracing technologies to test the hypotheses that some cells are primed to undergo WGD through endocycling or cell-cell fusion and that active polyploidization is a mechanism to resist chemotherapy. To deconvolve WGD by endocycling from WGD by cell-cell fusion, we transduced the TNBC cell line HCC1806 to create parallel populations with transcribed DNA barcodes on H2B-GFP or H2B-mCherry. All experiments were performed with homotypic cocultures containing equal proportion of cells from each fluorescent barcode population. With this method, ploidy alterations due to endoreplication were identifiable as monofluorescent single-barcoded cells with increased ploidy, while ploidy changes due to fusion were identifiable as double positive (GFP+mCherry+) double-barcoded cells with increased ploidy. The cell population was treated with an LD75 dose of doxorubicin and parallel plates were monitored by live-cell imaging. At each timepoint (pre-treatment, then 3, 5, and 14 days post-treatment), triplicate plates were stained with Hoechst and sorted into two fractions for lysis and DNA extraction: Near diploid (~2N) and ii) Hyperploid (&amp;gt; 4N). Barcode composition of cells from each fraction and each timepoint was determined through Illumina sequencing of barcode amplicons. Here, we will present preliminary results revealing the subclonal dynamics of gross ploidy alterations through normal culture conditions and chemotherapeutic perturbation. This study will elucidate whether pre-existing or de novo polyploidy promotes cell survival during chemotherapy, and determine if gross ploidy alterations occur randomly or through deterministic selection. Citation Format: Andrea L. Gardner, Lan Zheng, Patrik Parker, Kennedy Howland, Daylin Morgan, Amy Brock. The subclonal dynamics of gross ploidy alterations in TNBC cells under chemotherapeutic pressure [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 122.
Abstract 2621: Characterizing MEK1/2 degradation in K-ras mutant cells
Authors: Carlos Herrera-Montavez, Alison M. Kurimchak, Jian Jin, James S. Duncan
Journal: Cancer Research (2023)

Abstract Activating KRAS mutations frequently occur in several cancers including the majority of pancreatic ductal adenocarcinoma (96%), ~50% of colorectal cancers, and ~30% of lung adenocarcinoma. It has been shown that mutant K-ras preferentially signals through RAF-MEK-ERK signaling and that blockade of this pathway is essential for tumor regression. However, targeted MEK inhibitors (MEKi) have shown limited clinical benefit in the treatment of K-ras mutant cancers due to resistance caused by the feedback activation of the upstream kinase CRAF. Recently, PROTACs (Proteolysis-Targeting Chimeras) targeting MEK1 and MEK2 were developed, providing a new therapeutic strategy to degrade MEK1/2 in K-ras mutant cancer cells. Due to the fact that feedback-induced CRAF causes MEKi resistance in K-ras mutant cells, we postulated that degrading MEK1/2 could bypass CRAF-mediated resistance. Indeed, treatment of MEKi-sensitive or resistant K-ras mutant cell lines with MEK1/2 degraders rapidly reduced MEK1/2 protein levels and downstream ERK signaling causing growth inhibition and apoptosis. Proteomics characterization of K-ras mutant cell lines following MEK1/2 degrader or inhibitor treatment revealed MEK1/2 degradation exhibited distinct signaling pathway responses compared to inhibition. Together, our studies showed MEK1/2 degraders represent a promising avenue for the treatment K-ras mutant cancers that can by-pass resistance mechanisms observed with traditional MEK1/2 inhibitors. Citation Format: Carlos Herrera-Montavez, Alison M. Kurimchak, Jian Jin, James S. Duncan. Characterizing MEK1/2 degradation in K-ras mutant cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2621.
Abstract 2637: Novel folate receptor alpha-directed antibody-drug conjugate PRO1184 demonstrates broad antitumor activity with a promising safety profile in preclinical models
Authors: Lei Wang, Haidong Liu, Chang Zhou, Tae Han, Baiteng Zhao, Zhu Chen
Journal: Cancer Research (2023)

Abstract Folate receptor α (FRα) is overexpressed in a range of solid tumors with limited expression in normal tissues, hence an attractive target for an antibody-drug conjugate (ADC). PRO1184 is comprised of a human monoclonal antibody that selectively binds FRα, a novel cleavable hydrophilic linker, and a topoisomerase 1 inhibitor payload, exatecan. Previous studies established that a) PRO1184 exerts potent antitumor activity in cell-derived xenograft (CDX) models representing ovarian, non-small cell lung, and breast cancer, b) with pharmacokinetics (PK) akin to that of the unconjugated parent antibody in rats, and c) with a preliminary safety profile that was more favorable than a DXd-based ADC in cynomolgus monkeys. Further characterization of the activity and safety of PRO1184 is reported here. PRO1184 displays strong binding affinity, rapid internalization, and potent cytotoxicity with the HCC1954 (breast cancer), JEG-3 (choriocarcinoma), and HEC-1-A (endometrial cancer) cells, in vitro. PRO1184 at a single dose of 5 mg/kg produced marked tumor growth inhibition in CDX models with all three cell lines. In 14 patient-derived xenograft (PDX) models encompassing ovarian, gastric, breast, and non-small cell lung cancer, PRO1184 at a single dose of 5 mg/kg elicited robust antitumor activity in all four tumor types, with ORR and CR accomplished in 10 and 3 out of the 14 models, respectively. Antitumor activity was observed in xenografts with both high and low FRα expression, suggesting that PRO1184 may benefit patients with a wide range of FRα expression. Two DM4-based benchmarking ADCs produced modest to negligible tumor growth inhibition in head-to-head comparisons in the CDX and PDX studies. In a GLP cynomolgus monkey toxicity study for PRO1184, main treatment-related findings were consistent with those associated with exatecan and included reversible gastrointestinal and hematologic toxicities. There were no toxicity findings in lungs, which may translate to a lower risk of interstitial lung disease (ILD) compared to DXd-based ADCs in the clinic. In summary, PRO1184 is a promising development candidate for the treatment of FRα-expressing solid tumors. A first in human phase 1/2 study in patients with advanced solid tumors is currently recruiting (NCT 05579366). Citation Format: Lei Wang, Haidong Liu, Chang Zhou, Tae Han, Baiteng Zhao, Zhu Chen. Novel folate receptor alpha-directed antibody-drug conjugate PRO1184 demonstrates broad antitumor activity with a promising safety profile in preclinical models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2637.
Abstract 2646: Screening the membrane proteome to determine antibody specificity and de-risk CAR-T cell development
Authors: Joseph Rucker, Rachel H. Fong, Tabb Sullivan, Carmen Navia, Brad Screnci, Rona Wilf, Benjamin J. Doranz
Journal: Cancer Research (2023)

Abstract Rigorous specificity analysis is critical for the development of antibody-based therapies, as even minimal off-target binding can lead to toxicity and clinical failures. Long believed to be exquisitely specific, recent preclinical data and our own work indicate that monoclonal antibodies (MAbs) frequently (~25%) display cross-reactivity. In many cases, off-target interactions occur with unrelated proteins that cannot be predicted by protein sequence homology. Cross-reactivity can lead to serious or even life-threatening consequences especially when MAbs are configured as bispecifics, antibody-drug conjugates (ADC) or CAR-T cell therapies, and IND applications for biotherapeutics require cross-reactivity assessment to prevent adverse events. Tissue cross-reactivity (TCR) studies have traditionally been used to screen for off-target binding, however, with poor predictive value for in vivo safety and toxicity. We developed the Membrane Proteome Array (MPA) platform to de-risk MAb-based therapeutics by testing for specificity across 6,000 human membrane proteins expressed in live cells. In contrast to TCR studies, proteins in the MPA exist in their native conformations and are not altered by fixation. The MPA assesses binding interactions by high-throughput flow cytometry allowing for high sensitivity detection and rapid analysis. We will discuss the importance of early-stage specificity testing to expose possible toxicities and present case studies for antibody and cell therapy profiling. MPA data have been used in numerous successful regulatory applications and may be used to replace or complement other cross-reactivity studies. In particular, MPA profiling has been used in IND applications for CAR-T and cell-therapies where conventional immunohistochemical binding assays did not suffice. Citation Format: Joseph Rucker, Rachel H. Fong, Tabb Sullivan, Carmen Navia, Brad Screnci, Rona Wilf, Benjamin J. Doranz. Screening the membrane proteome to determine antibody specificity and de-risk CAR-T cell development [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2646.
Abstract 2624: Assay toolkit for the discovery of new RAS pathway inhibitors
Authors: Ekaterina Kouznetsova, Lauren S. McCauley, Rebecca Eells, Elaine Steinke-Neal, Timothy Sullivan, Louis Primavera, Charles Longen, Haiching Ma
Journal: Cancer Research (2023)

Abstract The small GTPase KRAS is a known oncogene that is very frequently mutated in a variety of cancers. Over the past several years, there has been a resurgence of interest in KRAS drug discovery following the identification of new inhibitor target sites and several molecules entering clinical trials. We have produced proteins and set up assays for a large collection of Ras variants, guanine nucleotide exchange factors and effectors to facilitate drug discovery activities targeting KRAS/MAPK pathway. RBC’s extensive kinase assay portfolio enables identification of kinase inhibitors downstream of Ras. This poster will summarize our most recent assay development efforts for biochemical and biophysical assays for these targets. Citation Format: Ekaterina Kouznetsova, Lauren S. McCauley, Rebecca Eells, Elaine Steinke-Neal, Timothy Sullivan, Louis Primavera, Charles Longen, Haiching Ma. Assay toolkit for the discovery of new RAS pathway inhibitors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2624.
Abstract 2643: BL-M07D1, a novel HER2-targeting ADC, demonstrates potent anti-tumor efficacy in preclinical pharmacodynamic models
Authors: Weili Wan, Shuwen Zhao, Shi Zhuo, Yong Zhang, Lan Chen, Gangrui Li, Jahan Salar Khalili, Sa Xiao, Yongqi Yan, Xuejiao Shen, Yi Zhu
Journal: Cancer Research (2023)

Abstract HER2 is a member of the epidermal growth factor receptor family. Activation of the HER2 signaling pathway has been shown to strongly promote carcinogenesis. It is therapeutically targeted in cancer owing to its overexpression and pathway dependence in a variety of human carcinomas, especially human breast cancers. We created a promising therapeutic anti-tumor agent, BL-M07D1, an anti-HER2-Ed-04 ADC. It is comprised of a humanized anti-HER2 antibody Trastuzumab, a cathepsin B cleavable linker, and a novel topoisomerase I inhibitor agent (Ed-04), which is a derivative of the alkaloid camptothecin, driving cell cycle arrest at the S phase and subsequent apoptosis. The BL-M07D1 drug-to-antibody-ratio is 8:1 (DAR=8), similar to Trastuzumab Deruxotecan (DS-8201), while possessing a more stable linker. To evaluate the pharmacological potential of BL-M07D1, xenograft tumor inhibition assays were used to compare BL-M07D1 with the commercialized HER2-targeting ADCs, T-DM1 and DS-8201, which have been approved worldwide for patients with HER2-expressing tumors. Results from the in vivo murine studies show that BL-M07D1 has strong tumor inhibition effects in multiple cell line-derived xenograft (CDX) tumor models. 1) BL-M07D1 exhibited better anti-tumor efficacy than DS-8201 in CDX with low HER2 expression, human epidermal cancer A431 and human non-small cell lung cancer NCI-H1975. Both models are considered be T-DM1-insensitive. 2) BL-M07D1 exhibited better anti-tumor efficacy in comparison to either T-DM1 or DS-8201 in a CDX with JIMT-1, a HER2-positive human breast cancer cell line. 3) BL-M07D1 exhibits potent bystander effects in a heterogeneous xenograft model of HER2-positive and HER2-negative tumor cells composed of NCI-N87 and MDA-MB-468 cells. In this model, BL-M07D1 exhibited stronger tumor inhibition than T-DM1, consistent with bystander effects that are also exhibited by DS-8201. In conclusion, in vivo studies suggest that BL-M07D1, a novel HER2-targeting ADC, is potentially more efficacious in a broader patient population than T-DM1, and mediate superior anti-tumor efficacy than DS-8201. The clinical phase I is under way and the available data exhibit excellent efficacy in breast cancer therapy with acceptable tolerability. Citation Format: Weili Wan, Shuwen Zhao, Shi Zhuo, Yong Zhang, Lan Chen, Gangrui Li, Jahan Salar Khalili, Sa Xiao, Yongqi Yan, Xuejiao Shen, Yi Zhu. BL-M07D1, a novel HER2-targeting ADC, demonstrates potent anti-tumor efficacy in preclinical pharmacodynamic models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2643.